Burglar-alarm



(No Model.)

0 B. WEAVER. BURGLAR ALARM.

. Patented Sept. 15, 1896.

ATTOR/VE XS WITNESSES:

m: Nonms PETERS co Pnarournu. wAsmuoToN, o c

Nrrn

rnrns ATENT rrrcn.

BU RG LAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 567,872, dated September 15, 1896.

Application file December 13, 1895. Serial No. 572,077. (No model.)

To all whom it may concern.-

Be it known that I, OSCAR B. WEAVER, of WVilliamsport, in the county of Lycoming and State of Pennsylvania, have invented certain new and useful Improvements in Burglar- Alarms, of which the followingis a full, clear, and exact description.

.This invention relates to an alarm in the form of a bell adapted to be secured to the inner side of a door above the lock and designed to be sounded upon the turning of the door-knob and thus give notice that some person is endeavoring to gain admittance.

A main object of my invention is to provide a simple means by which the alarm may be easily connected with or disconnected from a door-knob.

I will describe an alarm and knob-attachment devices embodying my invention, and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a partial elevation and partial section on the line 1 1 of Fig. 2 of a device embodying my invention. Fig. 2 is a partial side elevation and partial section thereof, and Fig. 3 is a perspective view of a knob-attaching device.

Referring to the drawings, A designates a gong supported on a frame a, extended from a base-plate a. Forward of the base-plate and supported thereby is a front plate a there being a space between the said two plates. On a shaft having bearings in the plates a a is a gear-wheel A, meshing with a pinion a also having bearings in the plates a a On the shaft of the gear-wheel A is a pinion a, engaged by a sector-gear A on the upper end of a lever A pivoted between its ends on a pin at the lower portion of the plates a a and the portion of this lever extended below the gong is longitudinally slotted, as at a T he shaft of the pinion a extends through the plate a and on its outer end is secured a crank-disk B, having a wrist-pin b. Oppositely-extended hammers B have their stem portions extended through guides Z) on the front plate, and these stem portions are pivoted on the wrist-pin b. A weighted balance-arm b is suspended from the wrist-pin b and extends through a guide-loop b on the front plate a This arm 17 and the weight thereof serve to balance the parts with which the arm is connected.

O is an arm having a forked lower end adapted to engage over the sleeve portion 0 of a door-knob. When the forked portion is passed over the sleeve, a screw 0 is passed through perforations in the ends of the fork members beneath the sleeve, and a clampingscrew 0 passed through a tapped hole in the upper portion of the fork, is adapted to clamp the arm firmly to the sleeve. Between lugs at the upper .end of the arm 0 is pivoted a latch consisting of a latch portion 0 and a finger-plate o extended in an opposite direction and at an angle to the part 0 The latch may be friction-tight between the lugs, so as to retain its position as set. In operative position the latch is turned to bring the portion 0 into the slot a and when in this position it is obvious that a rotary movement of the door-knob will swing the lever G and cause the alarm to be sounded. During the day the latch may be turned out of engagement with the lever, as indicated in dotted lines in Fig. 2, so that the knob may be turned without sounding the alarm. hen the latch is in connection with the lever, it will not allow the knob to be turned far enough to release the bolt 0 from its keeper, thus preventing the door from being opened.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. An alarm, comprising a bell and a lever for operating the same, an arm having a forked end to engage over the sleeve of a door-knob, fastening devices therefor, and a latch pivoted to the upper end of said arm and adapted to be moved into a slot in the lever, substantially as specified.

2. In an alarm, the combination with a rocking spindle, of an arm carried thereon, a pivoted latch, friction-tight on said arm, a sector on which the latch has sliding move ment, gearing with which the sector is en-' IOO gaged, a bell, and a hammer operated by the gearing, substantially as described.

3. In an alarm, the combination of a bell,

a crank disk, a clapper connected to the crank-disk, a Weighted arm also connected to the crank-disk, and means for operating the the crank-disk, and means for revolving the crank-disk, substantially as described. crank-disk, substantially as described.

4. In an alarm, the combination, of a bell, OSCAR B. WEAVER. 5 a crank-disk, two clappers extending oppo- Vitnesses:

sitely from the crank-disk and pivotally con- HARRY DIENER,

nected thereto, a Weighted arin connected to J NO. K. HAYS. 

